Absorption spectroscopy is often used in the content analysis of various substances. The content analysis may involve identification of the contents in the substances and/or an amount of a particular content in the substance.
In general, absorption spectroscopy includes spectroscopic techniques that measure the absorption of electromagnetic radiation as a result of the interaction of the electromagnetic radiation with one or more components of the substance. The absorption of the electromagnetic radiation is measured as a function of frequency or wavelength. The component(s) in the substance absorbs a certain amount of energy from the electromagnetic radiation. The intensity of the absorption varies due to the component(s) that are present in the substance and as a function of the frequency of the electromagnetic radiation.